Rubber Chicken in my gas tank....
 

So I'm trying to figure out why my car takes less fuel than it used to. The fuel tank capacity on my '89 CRX HF is supposedly 10.5 gallons (according to the owner's manual). However, where I used to be able to put ~9 gallons in when I was damn near empty (according to my gauge), I can only put between 5-6 gallons in now. WAIT, Don't assume it's my gauge's inaccuracy just yet! I have thought this myself. Recently, however, on multiple occasions I've driven the car down close to "E" to the point where my fuel pump starts sputtering, so I have to pull over to get gas (apparently I REALLY AM this low on fuel). But when I go to fill it, I only get 5-6 gallons in there. WHAT's THE DEAL?? Is there a gigantic air pocket somewhere in there? ...OR is there a rubber chicken displacing all the extra room in my fuel tank?! ANY help would be well appreciated.

I can got 75 miles past empty and still only put 10/11.9 gallons in, no big deal, the gauge is funky.

One other thing I should add is that when I manage to get 5-6 gallons in the tank, it's not just the pump kicking back at me. I fill this tank until I can see the level....so I KNOW it's full.

SVO Boy, I get what you're saying...but I'm not actually referring to my gauge. I'm talking about actual tank capacity & what it will take/hold. I've basically run this car to empty, having to take emergency exits off the highway to get to a gas station as it sputters on me....that's how I know I'm extremely low. But even being this low I can only get 5-6 gal in there. Anyone know what I mean?

You're fuel pump might be dying, making it sputter before it gets to the end of the tank.

There can always be deposits and such, but I doubt enough to fill several gallons, but then again, I've only ever replaced one gas tank.

Yeah. That's what I was worried about. That was the only thing that really made any sense to me. Of course, if I do replace the pump (drop the tank) at least I'll finally get a chance to start out fresh...since I'd plan to boil that tank out & get it cleaned properly. I've always wanted to do that.

I would suggest pulling the pump and sending unit out and inspecting it. It could be rust on the pickup sock. There should be a service port under the back seat or carpet, that allows access without dropping the tank. I do not know if your car has one though.

Yeah, there is an access port in the car that's not too difficult to get to. So you think I may just have some junk in there that starts clogging the sump when my fuel level gets too low then? Because the car runs fantastic otherwise (when the fuel level isn't very low).

I'm pretty sure that at least the first generation crx you can open the drain plug on the bottom of the tank, and check for sedement, but I would say that your suction hose on your pump has a hole in it or the screen is cloged like was said.

Yeah, thats my guess. I pulled a 93 civic pump and it had a 3-4" plastic mesh sock on it. Rust could clog it. Just pull and see. It may also have a hole in the pickup tube somewhere that might cause it to suck air. Inspect it closely when you have it out. I imagine the answer will be obvious.

I agree totally with "SVOboy"
 

It sounds as tho' you've been caught between the bean counters and Murphy's Law.... You often drive until the engine "sputters"...then find gas? Do you realize what is happening here? Your in-tank electric fuel pump is ANOTHER el cheapo unit (bean counter-mandated) which uses the gasoline as a coolant for the windings! Too low a gas level tends to expose the pump (parts that need additional cooling) to the non-liquid atmosphere. After many times of doing this...Oops! No pump! I found out the hard way...my '86 'Vette had a "miles left in tank" feature on the display (computer)...it didn't bother to tell me about "dry" (hot!) pump! So...long story short... I burned my pump out , searching for last- mile gas stations! No more! The 1/4 mark on my gauge spells "Empty"! No more problem....

Run it low and then pump the rest of the gas out into a gas can and measure how much you get out of it. Then do the pump - pickup removal - you may find a bunch of sand in the tank or you have a big dent in the bottom.

Did it have a beak and feet? Just wonderin' :D